The DDoS attacks that hit ABN Amro, ING and Rabobank over the weekend and on Monday, came from servers in Russia, according to security company ESET. The company adds that this does not automatically mean that the perpetrators are also in Russia, the Telegraaf reports.

The perpetrators used a so-called botnet – an army of hijacked computers and smart devices – to commit the DDoS attacks. Using the program Zbot, they remotely ordered these devices to visit a certain site en masse, thereby overloading the site’s server and crashing the site. The command and control servers are mainly in Russia, ESET determined.

The motive for these attacks is still unknown. The security company points out that the perpetrators can be anyone ranging from bored teenagers to state hackers – DDoS attacks are easy to buy online.

The Tax Authority’s site was also hit by a DDoS attack on Monday morning, leaving the site unavailable for a short period. ESET can’t yet say whether this attack is linked to the attacks on the banks.

The Ministry of Justice and Security called the attacks on the Dutch institutions very advanced, according to BNR. “But for example Dutch banks are known in Europe for having their cyber security in order. You often see that this provokes more advanced attacks. We are now fighting at a very high level”, the Ministry said. The Ministry can’t yet say who is behind these attacks.